i suggest using some small branches of manzanita to help scale the look of the tank as well as some rough stones for a sense of dimension. some fine mosses like fissidens, xmas or even weeping if you can find any would look great there. maybe a patch or two of belem in the back behind the stones could work as well.
ओं मणिपद्मे हूं
My life extends far beyond the limitations of me
Keeper of the LIST